Turnagain Pass Avalanche Forecast

A quick hitting storm rolled through the region yesterday bringing a much needed ‘re-fresh’ to Turnagain Pass. The Turnagain Pass SNOTEL station reported 9″ of new snow beginning yesterday around noon and ending last night around midnight. This usually equates to around a foot in the Alpine. The rain/snow line was hovering just under the parking lot elevations on the Pass, around 1,000′. We did get a report of a natural avalanche seen across the Arm from Girdwood, see that and additonal info HERE. This new snow is great news, but a new set of avalanche conditions will come with it as well. These are:

Wind Slabs:  Winds associated with the snowfall were moderate to strong from a generally Easterly direction. This is a perfect recipe for forming wind slabs above treeline that could be anywhere from 1-2+’ thick. How well these fresh slabs are bonding with the old snow surface is uncertain – and something to be wary of today. The old snow surface was quite variable, harboring sun crusts on Southerly aspects, wind crusts and loose faceting snow. All of these surfaces are not likely to promote good bonding right away and our hackles should be up. Things to watch for today:

   1-  Recent avalanches, the skies should clear for good visibility
   2-  Cracking or collapsing in the new snow
   3-  Slopes that have been windloaded – Avoid these today, give them a chance to adjust
   4-  SUN…. If the sun comes out slabs could release naturally with the warming!

Loose Snow Avalanches:  Once the sun does come out (today or tomorrow) damp/wet sluffs are likely to run naturally. These will also be easily triggered by a person. Sluffs should entrain mostly just the new snow, so how much new snow is on a slope will depend on how large the sluff is. 

Cornices:  Another round of snow and wind will only add to the weight of these truck size features overhanging many slopes. Extra caution is warranted when choosing how you travel along ridgelines – give cornices an extra wide berth. Also, limit time under these, they could fall on their own and the sun warming them will add to this possibility.

AVOID travel under glide cracks. This week has been a particularly active glide avalanche cycle. Glide cracks continue to threaten large areas of terrain throughout Turnagain Pass, Girdwood, and Summit Lake. There were several new glide avalanches seen Wednesday from the Seward Hwy, and a large glide released on the East face of Seattle Ridge a few days ago. Glide cracks are on all aspects within the mid-elevation band (1000′-2500′), and some areas like the SW face of Cornbiscuit and Tincan are covered. This avalanche problem is impossible to predict and is not associated with human triggers. We have been talking about the glide avalanche problem for over two months in the advisory and as long as glide cracks continue to open up, move and release, we will stress the importance of avoiding them.